Filtering apparatus



Jan. 19,1926. 1,570,374

P. H, CRAWFORD ET AL I FILTERI NG APPARATUS Filed March 51; 19 21 5 sheets-sheet 1 O O B O f I; .Z

, WITNESS \INVENTOR.

' fi/zmm a v mTToRNEYs Jan. 19- 19261:? I 1,570,374

i P. H. CRAWFORD El AL FILTERING APPARATUS Filed March :51, 1921 5 Sheets-Sheet 2' WITNESS INVENTOR Afi. (Amy/mm M0 fl If/444921 4 J W ATTORNEYS Jan. 19 1926.

P H. CRAWFORD Efm.

FILTERING APPARATUS Filed March 31, 1921 5 Sheets Sheet 3 Z fi a! o o M 4 .7 \J fz z \0 2f. 3 o r a Q A n a A O 6 4 x W.

o 7 fmV. 4 W a WITNESS W p R S ma W44 m w H P.'H. CRAWFORD ET AL Jan. 19 1926'.

FILTERING APPARATUS Filed March :51, 1921- 5 Sheets-Sheet 4 WITNESS INVENTOR 3/1 (mmw n/va I V v r B Jim/M WTTORNEYS Jan. 19 1926.

P. H. CRAWFORD :1- m.

FILTERING APPARATUS Fil'ed March 51, 1921 5 Sheets-Sheet s 5/ WITNESS I INVENTOR arm , I BY MMQZJKZW 'fi 7 v wATTORNEYS I Patented Ja g 6' UNITED PAUL I-I. CRAWFORD, F "PALOY v Amo,

" CALIFORNIA.

riL'raRIN P A ATUS,

Application filed Maren a1, 1921.,v Serial No. 457,249.;

'l 'o aZZ whom it may concern." v v Belt known that we, PAULH CRAWFORD,

a citizen of the United States, and a resident of Palo Alto, Santa Clara County,

State of California, and JOHN F. ABBjMih," I a subject of Holland, anda residentof Ofak I hind, county of Alameda, and State of California, have nventeda certain new and uselowing is a specification. The invention relates to an apparatus for v filtering or separating solids and semi-solids from liquids or fluids -containingfthe san'ie. The filter of our invention is capable of use in processes'where it'is desirable to sepa rate liquids or fluids from a mixture coir taining the same and solid ,or semi-solid materialand is particularly applicable toniet} allurgical, chemical, sugar manufacturing able material builds up as a eake on theifil tering medium due to the passage otthe filtrate through the-filtering medium,

removed singly from the apparatus, forrei placement or repair Avithout {interfering with the filtering operation E i A. further object erv he invention'is' to provide a filtering apparatus in which the solution remaining 1n, the cake or unfilterj able material may be substant ally ,entirely "replaced by Water or other liquid'prior to.

the removal of the cakefrom the filterunit; A further object of the inventio iiis to provide means for effectively'i'einovi ig the cakes from the filter units Without 'intei'fer-- ing' with theoperation of' the filter. I

The invention possesses other advaiitaforegoing, will beset forth at length in the following description Where .We' shall outline in full that form of the inventionwhich; i We have selected for illustration ;1n the; vdrawings accompanying and forming" part of the presllt specification. In saiddravw ings, We hare showg i one" specific embodiment of pin g nsrip' inventio f t t' s to' ful Filtering Apparatus, of which thef foland other processes, in which" the. u'nfilten.

An object'of the invention is to provide a the invention is to pro-- geous features, some of which," With thebe understood that :we do not .liinitv ourselves to such foi{m,fsi1 ice-the invention, as set forth in thelclaii'ns, may; befeinbodiedjin.

plurality of forms. 1

Tl e filtering apparatus of Louie invention coinp ses, generally, arotating fraine, the

lower jpo1'tion fof, -Whicli, is. disposed in the pulp Iboot or trough containing, l the, mix-i ture :of liquid a djsolid or;semi solid mate' v ,,ria 1., Mountedonthe frame are a plurality of; filter units arranged .Tin close relation;

and upon rotationf'of the frame-these units are moved through and submerged, in thepulp',then pass'froinlthe'pulp for-Idevvater-j ingpor solution replacement and] then subjected' to the operation ofl'm'echa'nism for;

removing the cake of u'ifi'filterable material from the unitsf The units :are preferably iotatablyinounted on. the-frame and-rotate V.

during the rotation of-the frame, so; that the processes of, filtering, dewateringyor replacement and removal ofthe cake are faeilitated. The filter unit 'may,be constructed infa plurality oft forms and in'the' a conip'anyihgdrawings, we have shown several typesfof,formsjvvhich"maybe a'dvan-.

tageou'sly employed. 'By' providing a' plu: rality of filter units arranged in close relation, a very large wfilteringlarea is provided in proportion to the ground' space oceupied by'the apparatus' rso that one filter .of this 7 type ;ma 7 supplant a v plur'ality, of filters of the drum typeLKThedrurn'type 'filter is HOW Tvvidely used and comprises drum or cylinder having a peripheral filtering surfacegjafid arrangedtorotate in a pulp bootinwhicha portion of the filtering slur}. face is submerged in thecontained pulp.

:11eferlring to the accompanying" drawings Figure lfis a vertical longitudinalsection of thejfiltering apparatus of our invention Fig. 2 is. air elevatioii 'ofoiieend of the apparatus. I i Fig. 3 isanelevation :of the opposite-i end of the" apparatus.

, -Fig.4fisa long tudinal through a l-filter 'unit in itsinounting v Y p V,

'of the: filterv unit aniie id view and its rotary mechanisms tially assembled 2 i F g,- 7 s a det l 'f tlie filtar nn t ryq i g a e;

Fig. 8 is an end elevation of the scraper and its operating mechanism, several filter units being shown in position.

Fig. 9 is a side elevation of the scraper and its operating mechanism, several filter units being shown in position.

Fig. 10 is a perspective View of a modified form of filter unit.

Fig. 11 is a perspective View showing an arrangement of adjacent filter units of the type shown in Fig. 10.

The filtering apparatus shown in the accompanying drawings comprises a rotatable frame comprising the spiders or end frames 2, secured to the hubs 3 which are secured to the shaft 45, rotatable in bearings 5 mounted on the pedestals '6. The shaft 1 is slowly rotated in any suitable manner, such as by the power driven worm 7 engaging the worm wheel 8 on the shaft. ,Mounted on the rotatable frame are a plurality of longitudinally disposed filter units 9, arranged in close relation and preferably rotatable on their axes. In the filter shown in Fig. 1, the filter units are cylindrical in shape and are disposed peripherally on the frame andare arranged in close relation, the spacing between the surfaces being sufficient to permit the formation of cakes of the desired thickness thereon without in terfering with the rotation of the filter units.

The filter unit shown in Fig. 4 comprises a cylindrical metallic shell. mounted on, se-' cured to and forming a tight joint with an axially disposed metallic conduit or pipe 12. The side 13 of the shell is depressed within the periphery of the end plates 14, forming a shallow recess, in which cocoa matting 15 or other comparable material is disposed. The cocoa matting is held in place by a sheathing 16 of canvas or other filtering medium, which is preferably wrapped spirally around the cocoa matting, as shown in Fig. 6. The liquid passing through the canvas passes through the cocoa matting filling to radially disposed pipes 17 connected to the pipe 12 and opening on the side of the cylinder and into the pipe 12. It is understood that a condition ofvacuum or reductionofpressure isproduced in the Pip h ch C ndi i n i t ansferr d to the filtering medium, causing the passage of liquid through the filtering medium. The pipe 12 extends froin both ends of the filtering unit cylinder, and is provided on both ends, substantiallymidway of theextended portions, with bearing heads 18 19,-

in which the pipe is jonrnaled. Each bear ing headis provided with a- 'tongue 21 which isdisposed in aperipheral radial slot 22 in the rotatable frameor carrier, the tongue being locked in the slotby a screw 23 pass ing through a portion of the frame and the tongue. By virtue of this mounting, 'afilter unit may be readilyremove'd from the carrier, by loosening or removing the screw 23 and then moving the unit radially from the carrier. The extending ends of the pipe 12 serve as handles for lifting and handling the filter unit.

Arranged between the pedestals 6, is a pulp boot or trough 24 which contains the mixture of liquid and solids or semi-solids to be filtered, and as the carrier rotates, the filter units are carried into the boot and are submerged in the pulp or mixture therein.

The bearing heads 18 and 19 are constructed to prevent the entry of solid and semi-solid material to the bearing. The bearing head 18, comprises a hollow bearing block 25 provided with an interior chamber 26 of greater diameter than the pipe 12, which pipe is provided with perforations 30 at that portion lying within the chamber to permit the passage of liquid or fluid from the pipe. The ends of the chamber are defined by annular bearing webs 27 which aremachined on their inner surfaces to coact with the rings 28 of Babbitt or other bearing metal secured to the pipe 12. The block is provided on both ends with packing glands 31 pressing the packing rings 32 into engagement with the pipe and holding the pipe against lon itudinal movement. Grease cups 33 are also provided for lubricating the bearings. The bearing block 19 is similar to the block 18 with the exception that the pipe 12 is imperforate.

The bearing block 18 is provided with means forconveying the filtrate therefrom.

Each bearing block 18 is provided with a nipple 341 which is connected to a filtrate discharge pipe 35 by a short length of hose 36 and a union 37 The various pipes 35, there being one for each unit, lead into a vacuum head 38 surrounding the main shaft 1 and each unit pipe 35 is provided with a valve 39 for cutting off communication with the unit. l/Vhen it is desired to remove a filter unit, the valve 39 is closed, the union 3? unscrewed, to break the physical connection and the holding screws 23 released. The removal of one unit will, therefore, not in terfere in any manner with the operation of the remaining units. provided with ports for directing the filtrate through the discharge pipe -11 and the wash ing solution through the discharge pipe 42, sothat the two liquids may be separately handled. Vacuum heads are well known in l the art and require no description herein.

As the filter units pass through the boot, the filtrate passes through the submerged filtering mediums, forming a cake thereon, which as it emerges from the boot carries in The vacuum head is 3 it a considerable amountof solution and,

since the solution is usually the valuable constituent of the 1nixjture,'the cake is subjected to washing to replace th solution ith Water and. o he. actien cf the vacuum,

:2. A filtering apparatus, con'iprisin g a rotatable carrier, a plurality of independent filtering units journaled on said carrier, means for rotating said units on said carrier and a receptacle for the material to be filtered through which the filter unitspass as the carrier is rotated.-

3. A filtering apparatus, comprising a rotatable carrier, a plurality of bearings removably secured to said carrier, a plurality of filter units journa'led in said bearings and a receptacle for the material to be filtered through which the filter units pass as'the carrier is rotated.

4. A filtering apparatus, comprising a rotatable carrier, a plurality of independent cylindrical filter units spaced apart around the circumference ofsaid carrier and a re ceptacle for the material to be filtered through which the filter units pass as the carrier isrotated.

5. Afiltering apparatus, comprising a rotatable carrier, a plurality of independent filter units rotatably mounted on said carrier, means operative by therotation of the carrier for rotating said filter units on their axes and a receptacle for the material to be filtered through which the filter units pass as the carrier is rotated.

6. A filtering apparatus, comprising a rotatable carrier, a plurality of independent filter units rotatably mounted on said carrier, a gear secured to each filter unit and a stationary rack arranged to be engaged by said gears.

7. A filtering apparatus, comprising a rotatable carrier, a plurality of independent filter units rotatably mounted on said carrier, a gear secured to'each filter unit, a receptacle for the material to be filtered through Which the filter units pass as the carrier is rotated and a stationary arcuate rack arranged above said receptacle and. arranged to be engaged by said gears.

8. A filtering apparatus, comprising a rotatable carrier, a plurality of hollow bearings secured to said carrier, filter units ournaled in said bearings and discharging filtrate thereinto, a filtrate head concentric with the axis oi said carrier and conduits connecting the bearings with the filtrate head.

9. A filtering apparatus, comprising a 1'0- tatable carrier, a plurality of hollow bearing blocks secured to said carrier, filter units journaled in said blocks and discharging filtrate thereinto, means forrotating said filter units on said carrier and means for conveying thefiltrate from said bearing blocks.

10. A filtering apparatus, comprisinga rotatable carrier, a plurality of independent cylindrical filterunits rota'tably mounted on said carrier, a receptacle for the material. to be filtered through which the filter units pass as the-carrier is rotated, and means Ior removing the cakes of unfilterable material fromsaid filter units.

IL .-A filtering apparatus, comprising a rotatablecarrier, a-plurality of filter units rotatably -mounted on said carrier, a receptacle for the-material to-be filtered through which the filtering units pass as the carrier is rotated, means for removing the cakes of unfilterable material from said filter units and means for rotating the filter unit in operative relation with the cake removing means.

12. A filtering apparatus, comprising a r0- ta-table carrier, a plurality of filter units mounted for rotation on said carrier, and means movable in an arc concentric with the axis of the carrier 'for removing the unfilterable material'from the filter units.

13. A "filter apparatus, comprising a rotatable carrier, a plurality of filter units moul'ited for rotation on said carrier, and a movable scraper for removing the unfilterable material fr'omsai'd filter units.

14. A filter apparatus comprising a rotatable carrier,'a plurality of filter units mounted ror'r'otation on said carrier, a movable scraper for removing the unfilterable materialjfrom said filter units and means for rotatingthe filter unitin operative relation with said scraper.

15. A filter apparatus, comprising a ro tatable "carrier, a plurality of filter units mounted for rotation on said carrier, a scraper movable in time with the bodily movement of'thefilter unit and means for rotating the filter unit in operative relation Wit-hthe scraper.

16. A filter apparatus, comprising a rotatable carrier, a plurality of filter units mounted'for rotation on said carrier, a

scraper movable in time with the bodily movement of the filter unit and means operativeby'the'movement of the scraper for rotating'the associated filter unit.

17. A filter apparatus, comprising a rotatable carrier, 'a plurality of filter units mounted for rotation on said carrier, a scraper movable intime with the carrier, and means for rotating the filter unit cooperating with thes'craper.

'18. A filtering apparatus comprising a rotatab-l'e carrier, a plurality of filter'units rotatably 'inounted onsaid carrier, a receptacle for thema'teri'alto be filtered through which the filter units pass as the carrier is rotated, means for directing sprays of washing liquid against saidunits as they are carried around by said carrier and means for rotating said units "on "said carrier.

In testimony whereof, we have hereunto set our'ha'nds. H r i p lAUL H- 'QBAW JOHN F. ABBEMA, 

